Eagle River Basin

Source Our computation, no independent reference · computed here from the screened DWR record Source Our computation, no independent reference · no independent reference; see /methods

This year, in context

In the weeks around 2026-09-29 (the newest reading on file), flows at the 16 ranked gages are running at a median 67% of their own long-term norm for this window — 11 below a typical year, 5 at or above. Driest relative to its record: EAST FORK EAGLE RIVER NEAR CLIMAX, CO, ranking 5th lowest of 25 years.

Gage flow trend & changepoints

Of the 23 gages with enough record, 1 is trending down and 0 up, and 1 carries a detected shift. The clearest is Eagle River at Red Cliff, its annual mean flow changing -2.56 cfs per decade (-6.2% of its median annual flow) over 95 years (p<0.0001). The other 22 show no clear signal either way.

22 other gage(s) show no significant trend or changepoint (not shown).

3 of those show a significant trend once extended backwards from a retired neighbour's record: Eagle River below Wastewater Treatment Plant at Avon (97 yr, decreasing, suspect); Eagle River near Minturn (97 yr, decreasing, suspect); Beaver Creek at Avon (64 yr, increasing, suspect). Those are reconstructions, not measurements — each gage's page shows both.

How the measurement network itself changed

This basin was not always measured the way it is today — the API-era record is dense and recent, the early record sparse. 16 gage(s) and 151 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1951. Every historical claim below is checked against this: long-term shifts that co-move with the growth of the network carry an explicit measurement-evolution caution, and abandonment screens whose idleness begins before the modern reporting era are flagged †.

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 9% of 2340 schematic-relevant structures. 0 year(s) clear the 30% coverage gate so far -- the trend activates automatically once qualifying years span a full decade. No action needed; the nightly backfill keeps extending the record.

Reach gain/loss shifts (1950–2026)

Mass-balance kinks computed for every summer month back to 1950 (1950 reach-snapshots) — which reaches gain or lose water, and how that has shifted across decades. Each shift is cross-checked against the observation record above: as more diversions became metered, "unaccounted" water shrinks mechanically, which can masquerade as a hydrologic shift.

• EAGLE RIVER BELOW GYPSUM, CO.: reach shifted from +1086 cfs to +94 cfs summer mean (more losing, p=0.002, 77 yr) [sedimentary plains/foothills: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]
• BEAVER CREEK AT AVON, CO: reach shifted from -4 cfs to -222 cfs summer mean (more losing, p=0.001, 49 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records] [measurement-evolution caution: this shift co-moves with the growth of the gage/metering network (rho=0.65) -- part of it may be unaccounted water becoming accounted, not hydrologic change]
• CROSS CREEK NEAR MINTURN, CO: reach shifted from +63 cfs to -94 cfs summer mean (more losing, p=0.002, 65 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]

Groundwater now has its own tab: 131 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 69 reservoir(s), end-of-year storage back to 1951, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 63-year window with full coverage (1964–2026), the dominant shared pattern across 3 gage(s) explains 89% of year-to-year variance (almost certainly a basin-wide climate/snowpack driver).

All gages in this window move with the shared pattern -- no localized outlier.

Structures most implicated by reconciliation (as of 2026-09-29)

Which structures' data absorbed the most correction when the current mass-balance snapshot was reconciled -- see the Historical tab for the full picture on any date.

• EAGLE-CROSS PUMP AND PIPELINE EAGLE RIVE (diversion): -2.4 cfs (25% of that reach's correction)
• EMPIRE ZINC CO IND WTR S (diversion): -2.4 cfs (25% of that reach's correction)
• GINN EAGLE RIVER DIVERSION NO. 2 (diversion): -2.4 cfs (25% of that reach's correction)
• VAIL/MEADOW MT MUN DIV 5 (diversion): -2.4 cfs (25% of that reach's correction)
• TERRELL AND FORD DITCH (diversion): -1.1 cfs (2% of that reach's correction)
• ARROWHEAD EAGLE R D & PL (diversion): -1.1 cfs (2% of that reach's correction)
• ARROWHEAD EAGLE R PMP ST (diversion): -1.1 cfs (2% of that reach's correction)
• BACHELOR GULCH FISHPONDS (diversion): -1.1 cfs (2% of that reach's correction)
• BEAVER CR SNOWMAKING RES NO 1 (diversion): -1.1 cfs (2% of that reach's correction)
• MCCOY SPRING (return): -1.1 cfs (2% of that reach's correction)

Source DWR administrative record · verify at DWR groundwater wells ↗ Source DWR administrative record · verify at DWR well permits ↗

273 water-level measurements across 131 monitored well(s) — 113 alluvial, 0 bedrock — plus 28 administered well(s) reporting metered pumping.

Well map

3D aquifer x-ray

Every aquifer unit as its own head surface, animated through time.

Water-table trends

Of 0 well(s) with enough record for a trend test: 0 declining, 0 rising.

Stream corridors — the surface connection

Where a reach's gain or loss has shifted, the wells within two miles of its anchoring gage and what their water table did over the same era.

EAGLE RIVER BELOW GYPSUM, CO.: 10 alluvial well(s) nearby. Glover screen: 0.3 cfs of nearby metered alluvial pumping → est. lagged depletion 0.3–0.3 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

BEAVER CREEK AT AVON, CO: 1 alluvial well(s) nearby

CROSS CREEK NEAR MINTURN, CO: 3 alluvial well(s) nearby. Glover screen: 0.3 cfs of nearby metered alluvial pumping → est. lagged depletion 0.3–0.3 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

Wells labeled by administrative world before anything else is said about them: tributary alluvium participates in the priority system; designated-basin and Denver Basin bedrock aquifers are governed differently and are excluded from stream-connection reasoning. Read bedrock declines differently too: deep bedrock aquifers recharge negligibly on human timescales, so a falling bedrock level is storage mining — effectively permanent — not a drought response that a wet year undoes. All screens advisory.

Source DWR administrative record · verify at DWR structure records ↗

69 reservoir(s) with 5,201 storage measurement(s), 1951–2025. Basin storage as of 2024-10-31 (the record's own end — reservoir records publish ~annually): 45,217 AF across 2 reservoir(s).

Reservoir map — how full is each vessel?

Basin storage, end of each water year

End-of-water-year totals; per-year reservoir counts shown because reporting coverage varies -- a total is only comparable to years with similar counts.

Largest reservoirs on record

Click a row to chart its full storage history, or open its dossier for rights, documents and dam-safety facts.

Source Independent agency measurement · fetched 2026-10-14 · verify at NRCS report generator ↗ Source Our computation, scored against a reference · NRCS forecast, graded here against the gage record

Snow-water equivalent, WY2027

A trace of snow at 1 of 3 sites (0.3 in of water at most); the median for the date is zero, so there is no percent to show yet. The snow year begins in October. The new water year began October 1; the chart fills in a day at a time as NRCS publishes each reading.

NRCS SNOTEL, daily. Sites are assigned to the district whose boundary contains them — the snow that feeds this district can also sit in a neighboring headwater district.

Two ways a snow year goes wrong (1979–2026)

A bad snow year here comes in two flavors (both called snow droughtA winter that shorts the snowpack. It happens two ways: a dry one, where the snow never comes, and a warm one, where near-normal snow falls but melts off weeks early -- and the river feels them differently.), and the river feels them differently. In 7 of the last 48 winters the snow never came — the pack peaked below 80% of its median. In 0 more, the snow came but left early — a near-normal peak melted out two weeks or more ahead of its usual date, sending the water down before the season needed it.

The snow never came: 1981, 2002, 2004, 2012, 2018, 2021, 2026.

Computed by this site from 3 SNOTEL sites’ full daily records (NRCS AWDB, back to 1979). Each year is measured against each site’s own multi-decade median — not the 1991–2020 normal the chart above uses — so the 1980s grade against a fair baseline. Peak and melt-out need 85% of the season’s days on the record; thin years are dropped, not guessed. Derived from snow measurements alone — it cannot tell dry-from-warm causes apart, only what the snowpack did.

Runoff outlook — Eagle R bl Gypsum

NRCS's final issue (2026-06-01) calls it even odds that at least 34 kAF arrives over 06-01 to 07-31 — 17% of a normal season; almost certainly at least 22, probably not more than 85. Our own record at this gage shows 34 kAF actually delivered. New forecasts begin in January. How to read these numbers →

We test a record-based adjustment of the April benchmark at every graded point. Here it did not beat NRCS over 51 replayed seasons (15% typical miss unadjusted vs 15% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →

How good are these forecasts here? (1979–2026)

Grading every April issue against what the river then delivered, measured at this gage’s own record — 47 seasons: the median miss of the 50% forecast is 15%, with a high bias of 2%, and the observed volume landed inside the stated 10–90% band 70% of the time (a calibrated forecast would say 80%).

Computed by this site: NRCS's archived April issues (their period as issued each year) against the observed volume in DWR’s published record; years with under 90% daily coverage are dropped, not summed. A grade of the forecast, never of the forecasters — these are hard rivers. How this point ranks among every graded Colorado forecast point →

What April snow has meant for this river (1979–2026)

Across 48 measured years, the season’s water has closely followed the April snowpack: a year opening April with 80% of median snow has typically gone on to deliver about 82% of a normal season (a snow-to-runoff elasticityHow strongly one number moves with another. A snow-to-runoff elasticity of 1.5 means a 10% shortfall in April snowpack has typically become a 15% shortfall in the season's water. of 0.9).

Computed by this site: the district’s April 1 SWE (% of each SNOTEL site’s own-record median) against the observed April–July volume at this gage (% of its median season) — a fixed window every year, unlike the forecast grades above, which use each issue’s own period. The slope is fit so single wild years can’t steer it (Theil–Sen, log space); years missing 10% of their days are dropped.

Source Our computation, no independent reference · computed here from the screened DWR record Source Independent agency measurement · fetched 2026-10-06 · verify at U.S. Drought Monitor ↗

Right now

This is the 1st-driest week 39 in 97 years of record at EAGLE RIVER AT RED CLIFF, CO. (as of 2026-09-21; this week’s flow sits at the 1st percentileRank against the record: a river at its 5th percentile is lower than it was in 95 of the past 100 years on this same date. for the date). On this week’s US Drought Monitor, Eagle County is 100% in D4 exceptional drought (2026-10-06). The law agrees: the most senior active call leaves 99% of this district’s decreed flow rights junior to the calling right this week.

Every year since 1910, week by week

Each thin row is a year at EAGLE RIVER AT RED CLIFF, CO.; each cell is one week’s flow ranked against the same calendar week of every other year — warm means dry for the date, blue wet, so seasonality cancels and droughts appear as warm bands. Gaps are missing record, never a dry river. Click a year to reconstruct it on the Historical tab.

This year against its analogs

Over the 31 weeks recorded so far, 2026’s weekly trace most resembles 2012 (mean gap 13.7 percentile points; next closest 2021 (14.1), 2002 (16.0)). The analog’s remainder is drawn as context — its ending is what happened to it, not a forecast for this year.

The Drought Monitor’s view since 2000

Mean share of area in each class across Eagle county — the counties this district’s gages sit in, which overlap the district imperfectly. The Drought Monitor weighs soils, vegetation and local reports; it is CONTEXT beside the river’s own record above, not the water-rights picture.

The law’s own drought gauge

When water runs short, administration answers: calls reach further back in time, and more decreed rights go junior to the calling right. This is that response, weekly since 2008 — the share of this district’s decreed flow rights junior to the most senior active call. Watch it spike in the named droughts below, and linger after the river recovers.

Computed from DWR’s call record (320 calls touching this district) against the district’s rights index. Scoping is deliberately coarse — a call’s own district, or districts named in its comments — and this is administration’s RESPONSE, not a per-structure verdict (each dossier’s curtailment card does that, with stream miles). A deepening call can also reflect growing demand, not only shrinking supply.

This basin’s droughts, by its own record

Detected mechanically: the 26-week smoothed percentile below the 30th for at least 20 weeks; recovered on regaining the 50th. The water-table clock compares each monitoring well against its own pre-drought median (the 3 years before onset) and dates the year the median well got back — the aquifer remembers longest, and “still below” is a finding, not a gap. The knobs are stated because the episode list depends on them — a different reasonable choice merges or splits episodes at the edges. Names are attached where an episode overlaps a drought Colorado already talks about.

When this basin claimed its water

Every bar is a year’s new appropriations (2,878 rights across 99 years of shared record), colored by that year’s wetness from the barcode above. Here the correlation is +0.07 — essentially no wet-dry pattern; here, law and settlement set the pace, not the weather. Across the state both behaviors exist: ephemeral southwest basins file after wet demonstrations, transbasin-source basins under drought — and the biggest statewide filing waves sat in the 1950s drought and after 2002, not in the wet 1980s–90s.

Appropriation dates are the CLAIMED initiation of a right, not the courthouse filing date; the record is survivor-biased (abandoned claims are absent, so failed dry-era scrambles are undercounted); and the big 1960s and 2000s spikes sit on legal events — the pre-1969-Act adjudication era and 2000s legislation — not on weather. A correlation here is a description, never a cause.

New to how a dry winter becomes a call on the river? Anatomy of a drought walks the chain in four minutes — snow to rivers to reservoirs to calls to the water table.

Who serves it, who protects it

Two registers the site fetches on their own schedules, read for this district. Neither is a DWR record; each links its own page and its agency.

Public water systems here

Source Register of another agency · fetched 2026-10-06 · verify at EPA SDWIS ↗

10 systems touch this district (10 community systems reporting 79,191 people served, a figure that counts a wholesaler's customers twice); none carries an open health-based violation on EPA's record.

and 2 more; the full directory filters by district.

Instream-flow rights held by the state

Source Register of another agency · fetched 2026-10-11 · verify at CWCB instream flow program ↗

79 reaches over 389.7 miles and 48 natural lake levels, held by the Colorado Water Conservation Board so that water stays in the stream. Every reach, with its schedule and case →

• Eagle River, 20.0 mi: 45 (10/1 - 4/30), 110 (5/1 - 9/30) cfs (appropriated 1980, 80CW0126) · dossier
• Gypsum Creek, 16.6 mi: 6 (1/1 - 12/31) cfs (appropriated 1980, 80CW0116) · dossier
• Eagle River, 12.8 mi: 50 (10/1 - 4/30), 130 (5/1 - 9/30) cfs (appropriated 1980, 80CW0124) · dossier
• Brush Creek, 12.0 mi: 12 (1/1 - 12/31) cfs (appropriated 1977, 77W3625) · dossier
• Eagle River, 10.1 mi: 35 (10/1 - 4/30), 85 (5/1 - 9/30) cfs (appropriated 1980, 80CW0134) · dossier
• Black Gore Creek, 10.0 mi: 4 (10/1 - 10/31) cfs (appropriated 1986, 86CW0230) · dossier

and 121 more on the district's instream-flow page.

What the water is like -- USGS sensors right now, where it has been sampled, the impaired-waters list, and how the tap water here stands with EPA -- is on the Water quality tab.

Designated groundwater basins are on their own page.

Source Adjudicated record · verify at DWR water-right transactions ↗ Source Adjudicated record · verify at DWR net amounts ↗

Decreed rights on this network run from 1880-10-20 to 2024-12-31. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 5% of a median irrigation season and 0% in a dry one. 25 abandonment screens and 194 compliance flags are listed below as leads for review — a screen is not an abandonment and a flag is not a violation.

Rights on file: 4157 across 2162 structure(s); 419 structure(s) carry 0 court-case references. Advisory reading aids on public DWR data — not administrative or legal conclusions.

Is the river getting harder to divert from?

Over 1988–2025, administration on this district has been tightening: 3 of 3 measures (days under callA senior water right demanding its water, which requires everyone junior on that stream to stop diverting until it is satisfied., calls set, seniorityColorado shares water by date: the earlier the right, the stronger its claim when the river runs short. "First in time, first in right." of the controlling call) are moving toward more administration, none the other way.

Why diversions stopped — call-based explanations

Sustained diversion stops matched to senior administrative calls.

• CASTEEL DITCH (3700531) DWR↗☆ stopped 2024-09-30 (31+ days) — call at GRAND VALLEY CANAL curtailing 100% of its decreed rate [heuristic-strong]
• BEMIS DITCH (3700510) DWR↗☆ stopped 2024-09-18 (42+ days) — call at GRAND VALLEY CANAL curtailing 100% of its decreed rate [heuristic-strong]
• BEECHER CREEK DITCH (3700509) DWR↗☆ stopped 2024-08-16 (76+ days) — call at HIGHLINE DITCH (BUZZARD) curtailing 84% of its decreed rate [heuristic-partial]
• CASTLE NO 1 DITCH (3700534) DWR↗☆ stopped 2024-08-02 (90+ days) — call at CAMP BIRD DITCH curtailing 100% of its decreed rate [heuristic-strong]
• C M STREMME GATES DITCH (3700548) DWR↗☆ stopped 2024-06-29 (124+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
• CREAMERY DITCH (3700560) DWR↗☆ stopped 2023-10-31 (366+ days) — call at MOCKING BIRD DITCH curtailing 71% of its decreed rate [heuristic-partial]
• CHATFIELD BARTHOLOMEW D (3700539) DWR↗☆ stopped 2023-10-30 (192+ days) — call at MOCKING BIRD DITCH curtailing 66% of its decreed rate [heuristic-partial]
• DAGGETT AND PARKER DITCH (3700561) DWR↗☆ stopped 2023-10-30 (139+ days) — call at MOCKING BIRD DITCH curtailing 54% of its decreed rate [heuristic-partial]
• DITCH NO 3 DITCH (3700568) DWR↗☆ stopped 2023-10-15 (198+ days) — call at BUFFALO DITCH curtailing 100% of its decreed rate [heuristic-strong]
• CASTLE NO 1 DITCH (3700534) DWR↗☆ stopped 2023-10-12 (217+ days) — call at BUFFALO DITCH curtailing 100% of its decreed rate [heuristic-strong]

Right yield — how often could these rights actually divert?

Share of irrigation-season days each structure's rights were not called out, derived from the 22-year district-scoped call record (senior right = floor, junior right = ceiling constraint). Call-record-derived; DWR's own analysis governs where available.

Abandonment radar (25 screens)

Absolute rights with 10+ years of no recorded diversions. Screens only — storage, alternate points, and plan operations can explain nonuse lawfully. And diversion REPORTING itself only reached its modern level ~1951 — idleness that begins before then may be unreported use, not nonuse (flagged † below).

• OHNECK NO 2 DITCH (3700738) DWR↗☆ (1917-05-01, 2.3 cfs decreed): last active 1951 — 69 years idle
• PETERSON NO 4 DITCH (3700759) DWR↗☆ (1906-08-29, 0.2 cfs decreed): last active 1952 — 68 years idle
• SHIVELY DITCH (3700802) DWR↗☆ (1892-11-01, 1.2 cfs decreed): last active 1953 — 67 years idle
• BIGHORN PIPELINE (3700881) DWR↗☆ (1963-04-04, 1.6 cfs decreed): last active 1953 — 67 years idle
• MAHONEY DITCH (3700690) DWR↗☆ (1927-04-01, 2.8 cfs decreed): last active 1955 — 65 years idle
• NOTTINGHAM DITCH (93) (3700733) DWR↗☆ (1887-05-26, 2.0 cfs decreed): last active 1955 — 65 years idle
• BIG SPRING (3700879) DWR↗☆ (1935-05-01, 0.1 cfs decreed): last active 1955 — 65 years idle
• BEAVER MEADOWS DITCH (3700507) DWR↗☆ (1923-09-01, 1.1 cfs decreed): last active 1956 — 64 years idle
• JOHNSON & HOWARD DITCH (3700666) DWR↗☆ (1900-05-14, 3.0 cfs decreed): last active 1956 — 64 years idle
• WELLS NO 2 DITCH (3700852) DWR↗☆ (1930-05-01, 2.4 cfs decreed): last active 1956 — 64 years idle

Compliance screens (194 advisory flags)

Screened 369 of 2162 structures with rights (415 have diversion history on file). A flag is a lead for expert review — augmentation plans, exchanges, and free-river conditions can make over-decree diversions lawful and are deliberately not modeled.

• NOTTINGHAM & PUDER DITCH (3700736) DWR↗☆: Observed p99 daily rate 55.5 cfs (max 55.5) exceeds total decreed absolute 24.6 cfs across 11400 recorded day(s).
• COLUMBINE DITCH HDG 3 (3704641) DWR↗☆: Observed p99 daily rate 36.0 cfs (max 66.6) exceeds total decreed absolute 30.0 cfs across 22790 recorded day(s).
• BOLTS DITCH (3700514) DWR↗☆: Observed p99 daily rate 31.7 cfs (max 31.7) exceeds total decreed absolute 30.0 cfs across 4392 recorded day(s).
• TERRELL AND FORD DITCH (3700830) DWR↗☆: Observed p99 daily rate 27.6 cfs (max 31.5) exceeds total decreed absolute 23.8 cfs across 15370 recorded day(s).
• COWEN SPRINGS (3700558) DWR↗☆: Observed p99 daily rate 26.5 cfs (max 26.5) exceeds total decreed absolute 3.0 cfs across 3148 recorded day(s).
• CREAMERY DITCH (3700560) DWR↗☆: Observed p99 daily rate 26.5 cfs (max 28.8) exceeds total decreed absolute 21.6 cfs across 18331 recorded day(s).
• EMPIRE ZINC CO PIPELINE (3700590) DWR↗☆: Observed p99 daily rate 23.4 cfs (max 23.4) exceeds total decreed absolute 16.0 cfs across 4394 recorded day(s).
• EMPIRE ZINC CO PIPELINE (3700591) DWR↗☆: Observed p99 daily rate 23.4 cfs (max 23.4) exceeds total decreed absolute 1.0 cfs across 4392 recorded day(s).
• C K P DITCH (3700545) DWR↗☆: Observed p99 daily rate 22.6 cfs (max 30.1) exceeds total decreed absolute 2.4 cfs across 20209 recorded day(s).
• EAGLE DITCH (3700579) DWR↗☆: Observed p99 daily rate 21.2 cfs (max 21.2) exceeds total decreed absolute 13.2 cfs across 3240 recorded day(s).

Seniority (top structures by decreed rate)

Recent inventory & legal-document changes

• 2026-10-09 — call released: 39534
• 2026-10-08 — call set: GRAND VALLEY CANAL (39690)
• 2026-10-08 — call released: 36734
• 2026-10-08 — call released: 38588
• 2026-10-08 — call released: 39264
• 2026-10-07 — call set: CORNELL DITCH (39681)
• 2026-10-07 — call set: MOCKING BIRD DITCH (39686)
• 2026-10-07 — call released: 39636

Water-court filings this month (division-wide)

9 applications in the 2026-09 resume for this basin's division — new rights, changes, augmentation plans — from the water clerk's statutory monthly notice (C.R.S. 37-92-302), the earliest public signal of a new claim. Filings are division-wide, not district-filtered: check the county column. Full resume PDF at the Judicial Branch →

Anyone affected may file a statement of opposition until 2026-11-30 (47 days left). C.R.S. 37-92-302(3): due by the last day of the second month following the filing month — computed, not legal advice; confirm with the water clerk.

Active substitute water supply plans in this district

Temporary State Engineer approvals to divert out of priority (37-92-308 / 37-90-137). A structure operating under one behaves differently under a call than its decreed rights alone suggest — the priority tables above don't know about these; this list does. Source: DWR’s active-SWSP register, refreshed nightly.